In this work, García Máynez exposes the supreme logical-legal principles, but does not follow the order adopted in the logic manuals. The first part of the book exposes "The supreme principles of legal logic" and the second deals with "Legal axiomatics"; in them he analyzes: the legal principles of contradiction and the excluded third party; the systematic study of cases of contradictory opposition between legal norms; the principles of sufficient reason and identity; the ontological foundation of the supreme legal-logical principles; the rules of conduct; the subjective right; the legal and the illegal; as well as the positive definition of the right to freedom and the abuse of the right, dealing finally with the legal axiomatics.

Since the legal doctrine is as rigorous and scientific as formal logic, the author exhaustively and systematically exposes the capital axioms of the formal ontology of law; First, it analyzes the conflicts between norms that belong to the same legal system, then discussing those raised by antagonistic prescriptions whose reason for validity is different, it also examines those that arise between precepts of a single legal system, analyzing those existing between norms originating from a source. common, to later study those that occur between precepts derived from different sources.

The a priori principles of all law, exposed in this work, are valid both for the law and for any legislator, and the reader will realize that these do not refer to specific legal contents, but to essential connections between the two forms of law. manifestation of normative consequences (legal duty and subjective right) and among those that can be assumed by legally regulated conduct; the forbidden, the ordered, the optional. In the same way, he will realize that both the principles of legal logic and the axioms of the formal ontology of law and the propositions that rest on them are not norms, but truths of reason.